Use-After-Free Vulnerability in Mozilla Firefox and Thunderbird Products
CVE-2025-1012

7.5HIGH

Key Information:

Vendor
Mozilla
Status
Firefox
Firefox Esr
Thunderbird
Vendor
CVE Published:
4 February 2025

Summary

A race condition during concurrent delazification in Mozilla Firefox and Thunderbird can result in a use-after-free scenario. This flaw occurs when specific versions of these products process certain memory operations simultaneously, leading to unpredictable behavior and potential exploitation. Users of Firefox versions earlier than 135 and specific versions of Firefox ESR and Thunderbird should be aware of this vulnerability and consider updating to secure versions available to mitigate possible risks.

Affected Version(s)

Firefox < 135

Firefox ESR < 115.20

Firefox ESR < 128.7

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1939710
https://www.mozilla.org/security/advisories/mfsa2025-07/
https://www.mozilla.org/security/advisories/mfsa2025-08/

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
High
Privileges Required:
None
User Interaction:
Required
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Nils Bars
.